Mixing 4k video with 1080p and keeping them both Full screen

Mixing 4k video with 1080p and keeping them both Full screen
by Tim Applegate on Jul 27, 2016 at 3:11:22 pm

If I start with a 4k file and blend in a 1080 file, the 1080 portion is considerably smaller due to the resolution. If I start with a 1080p file and blend in the 4k file the 1080 starts in full screen and zooms in on the 4k file with an extreme "crop."

Any suggestions to being able to blend both resolutions with out zooming or reducing the screen size 1080 file